const arrLike = {0:1,1:2,length:2}
// for(let i=0;i<arrLike.length;i++){
//     console.log(arrLike[i])
// }
arrLike.length--
console.log(arrLike)


const obj = {
    a:1223
}
console.log('a' in obj)
Object.keys(obj).map(item=>{
    if(item in obj){
        console.log(item)
    }
})

const arr = [12, ,8]
const arrLike1 = {length:arr.length}
for(let i=0;i<arr.length;i++){
    console.log(arr[i],'arr[i]')
    arrLike1[i] = i in arr ? arr[i] : undefined
}
console.log(arrLike1,'arrLike1')